Abstract

Genetic diversity for grain nutrients in wild emmer wheat –
A potential for wheat improvement
Merav Chatzav1‡, Zvi Peleg1‡, Tzion Fahima2, Ismail Cakmak3, Yehoshua Saranga1*
Abstract
• Background and Aims - Mineral nutrient malnutrition, and particularly deficiency in zinc (Zn) and iron (Fe), afflicts over three billion people worldwide. In the current study wild emmer wheat (Triticum turgidum ssp. dicoccoides (Körn.) Thell.), the progenitor of domesticated wheats, was tested for (i) genetic diversity in grain nutrient concentrations, (ii) the associations among grain nutrients and their relationships with plant productivity, and (iii) their association with the ecogeographical origin of wild emmer accessions.
• Methods - A Total of 154 genotypes, including wild emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this two-year field study for grain protein (GPC), micronutrients (Zn, Fe, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulphur) concentrations.
• Key Results - A wide genetic diversity was found among the wild emmer accessions for all grain nutrients. The concentrations of grain Zn, Fe and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed a significant genetic variation between and within populations for all minerals. Association between soil characterise of the site of collection and grain nutrient concentrations showed negative associations between soil clay and GPC and between Zn in soil and in grain, the latter suggesting that the greatest potential for grain nutrient mineral is expected in populations from mineral deficient soils.
• Conclusions – Wild emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat genepool.
Key words: Triticum turgidum ssp. dicoccoides, grain quality, protein, zinc, iron, wheat improvement, micronutrients, macronutrients